The present invention relates to a static neutralizer which emits ions in order to neutralize static electricity.
Static neutralizers have long been used for the purpose of suppressing or neutralizing static electricity. In known constructions, ion emitters are provided, having ionizing points, being made of conductive material and connected to a source of electric energy. The ion emitters may be supported in an appropriate structure, and often this has been some non-conductive material. A ground potential reference has been provided, as by a metal channel provided on the body of insulating material and connected to ground. Examples of such constructions include Muller et al U.S. Pat. No. 3,111,605 and Schutz U.S. Pat. No. 3,283,209. Also relevant in Radington-Meech et al U.S. Pat. No. 3,470,416. In some instances there has been provided in the prior art an insulated conductor, positioned in a supporting structure, with pins or needles passed through the insulation and through the conductive element, thereby forming the ion emitter and its connection to a linear conductor wire which may be connected to a source of electrical energy, such as high voltage alternating current. An example of this latter construction in Testone U.S. Pat. No. 3,746,924.
The prior art static neutralizers and ion emitters as above described have generally been provided for use in various mechanical processing machinery, and typically have been in the form of linearly extending bars.
Static neutralizers have also been utilized in various film feeding operations, including photographic film processing apparatus. In such apparatus, it is important that a suitable supply of ions be provided, without the emission of light from the static neutralizer, since in such apparatus, the emission of light would harm the photographic film. There are several products which have been on the market which are intended to generate ions, from static electricity and neutralization, without the emission of light. In one, a generally tubular ion generator has been provided with an angled extension elbow, intended to prevent the escape of light into the interior of the photographic film processing apparatus, and this static neutralizer is known to require a flow or air under pressure past the ionizing points, in order that a suitable supply of ions be introduced into the film processing apparatus. This has required, therefore, the provision of a source of air under pressure, and an additional conduit for the air extending into the film processing apparatus, to the ion generator. Another commercially produced apparatus has utilized a so-called static bar, which has linearly extending with a number of ionizing points, together with a pair of plates intended to shield the photographic film from any light emission at the exposed ionizing points. This construction was of low efficiency, requiring perhaps 3-4 minutes to obtain static neutralization, thereby requiring a long start-up time in order to avoid the risk of static charges which would damage the photographic film.
A further known ionizing air generating apparatus is disclosed in Testone U.S. Pat. No. 3,671,049, which discloses an ion generator in combination with the presser foot of a sheet feeding apparatus. The presser foot is disclosed as having a vertical passage, connected with a plurality of diverging horizontal passages, and a metal tube is inserted into the vertical passage. An ion generator is provided, including ionizing points extending through the presser foot, and into the metal tube. In this construction, since conventional paper was being fed in an open room, the emission of light from the ionizing points was not a matter of consideration. The ions generated at the ionizing points were caused to be blown through the metal tube and into the noted connecting passages in the presser foot, in order to distribute a flow of ionized air, although it is recognized that the proximity of the inner wall of the metal tube to the ionizing points caused a significant portion of the ions generated to be absorbed by the metal tube, with resulting decrease in ion output from the device. This made the device less efficient than desirable, and efficiency was further impaired by the restricted size of the outlet passages.
A static neutralizer is provided having a body of insulating material with a cavity, ionizing points of ion emitters being located in the cavity. The cavity is connected by an angled passage of substantially the same cross sectional area as the cavity to the exterior, the passage being at an angle so as to prevent the emission of light from the ionizing points out of the static neutralizer body. The surface of the body of insulating material is light absorbing, to prevent the reflection of light from the ionizing points, outwardly of the body. A metal sleeve surrounds the insulating body, having an upper edge which lies in a common plane, the ionizing points also lying in this plane. A coaxial cable is provided having an inner conductor, a surrounding insulating layer, and an outer conductor provided by woven metal threads. The outer conductor is connected to the metal sleeve, and the inner conductor and insulating layer extend through the metal sleeve and into the insulating body, the ionizing emitters in the form of pins or needles passing through the inner conductor and insulating layer and thereby being connected to the inner conductor. The inner conductor is connected to a source of electricity, and the outer conductor is grounded. A sheath of light impervious material, such as a tube of black plastic, encompasses the outer conductor, to prevent the escape of any light which might be caused by the field between the inner and outer conductors. The static neutralizer is of very small dimensions, being encompassed within an envelope of 1" by 11/2" by 13/4".
Among the objects of the present invention are to provide a static neutralizer of small size, capable of emitting a large amount of ions, and without emitting light. Another object is to provide a static neutralizer which, when used in connection with photographic film processing equipment, can provide a large amount of ionized air in a very short time, as within a fraction of a minute, and without requiring the use of compressed air. Still another object of the present invention is the provision of a static neutralizer in combination with a high voltage conductor which will prevent emission of light from both the neutralizer and the conductor.
Other objects and many of the attendant advantages of the present invention will be readily understood from the following drawings and description.